1. Field of the Invention
The present invention relates to a method and system for reducing the volume of bulk material, and specifically, the present invention relates to a method and system for gasifying waste to produce energy.
2. Background of the Invention
Municipal landfills are filling up. While recycling efforts are ongoing to reduce the volume being landfilled, the bulk of municipal solid waste is buried.
Efforts are ongoing to reduce waste volumes via thermal degradation. U.S. Pat. No. 5,387,321 (to Holland) uses microwave electromagnetic radiation (EMR) heating, adding scrap tires and the like as absorbers for microwave energy.
U.S. Pat. No. 5,487,873 (to Bridges, et al.) uses radio frequency EMR to accomplish pyrolysis in an oxygen free atmosphere.
U.S. Pat. No. 5,069,765 (to Lewis) and U.S. Pat. No. 4,472,245 (to Halm) describe electric arc methodologies to also pyrolyze organic materials.
U.S. Pat. No. 6,155,182 (to Tsangaris et al.), U.S. Pat. No. 6,018,471 (to Titus et al.) and U.S. Pat. No. 5,280,757 (to Carter et al.) disclose methods of using plasma arc technology for driving the pyrolysis of organic feed material.
Recently, plasma technology has been considered in the thermal degradation of garbage. Users of the energy provided by plasma systems pay approximately $58 to $60 per MW-hour, compared to $62 per MWh for power provided by typical biomass-fueled facilities. However, plasma systems are typically stationary. And the capital outlays for such systems are enormous, at well over $150 million per plant. Also, the initial energy inputs are high.
All of the aforementioned technologies, using EMR, plasma generation or electric arc methods, are limited in through-put capacity to just a few tons per day, and have been used economically only for destroying trash with high disposal costs, such as medical, industrial hazardous waste, and nuclear waste.
A need exists in the art for a system and method for reducing the volume of municipal solid waste prior to disposal. The system and method should be economical such that energy created as part of the volume reducing effort can be utilized to provide energy to downstream processes, such as drying operations, boilers or steam turbines. The system and method should be transportable. Also the system and method should be brought up to operational status within 60 minutes after being charged with material to be reduced.